KONSTANTIN TSIOLKOVSKY (1857-1935) Pioneering Russian scientist and rocket designer who laid out the basic principles of modern space flight. Rare, superb partial A.Ms.S., 2pp. sm. folio, [n.p., ca. 1931], in Russian. Untranslated, but undoubtedly part of his notes on space travel and bearing a mathematical table at bottom with a sketch of a rocket in flight drawn at top! Signed at lower-left, the signature partly affected by dampstaining yet entirely legible, typical aging and wear, overall good to very good. Certainly worthy of further research!            $700-900